江西九连山区常绿阔叶林林冠截留量的估算

THE ESTIMATION OF THE CROWN INTERCEPTION OF THEEVERGREEN BROADLEAVED FOREST IN THE JIULIANMOUNTAINOUS DISTRICT, JIANGXI PROVINCE

为了研究常绿阔叶林小流域的水分平衡，我们在江西九连山区进行了３ａ林外雨量、林内雨量和树干流量的观测，并据此进行了年林冠截留量的估算。观测结果表明，林冠截留率由一次降雨量为０．４～１ｍｍ的７８．１％逐步降低到一次降雨量为６０ｍｍ的３．４％～３．６％。一次降雨量大于６０ｍｍ时，林冠截留率基本稳定在这一百分数。１９８８、１９８９和１９９０年３ａ的年降水量在１７１８．５～２１１６．５ｍｍ之间。估算结果表明，年林冠截留量在３００～３４０ｍｍ之间，约为年降水量的１６％～１７．５％。

n order to research into the moisture balance of a small watershed covered by evergreen broadleaved forests, we have made the observation of the precipitation outside and inside the forest area and the stemflow in the Jiulian mountainous district, Jiangxi Province, for three years. On this basis we made the estimation of the crown interception. The results of observation show that the rate of the crown interception is 78.1% of the precipitation when the precipitation is 0.4～1 mm at a time, and it declines to 3.4%～3.6% when the precipitation is 60 mm at a time. But when the precipitation is over 60mm at a time the rate of crown interception is basically stable, being 3.4%～ 3.6%. The total annual precipitation in 1988,1989 and 1990 is 1 718.5～2 116.5mm. The results of estimation show that the total annual crown interception of the three years is 300～340 mm, which makes up about 16%～17.5% of the total annual precipitation.